As is well known, conventional emergency vehicles include noise making and lighting systems intended to warn persons in the area of their approach. Typically such emergency vehicles have sirens and lighting systems mounted on the top, the hood or the fenders. Heretofore mounting of warning systems in such locations on the vehicle has been necessitated by the size and configuration of available warning systems. However such locations produce many undesirable effects. For example, a typical siren mounted on top the vehicle, its hood or fenders produces a great deal of noise within the vehicle. If mounted on the hood of conventional type vehicles, engine heat greatly diminishes the longevity of the device. Further it has been shown by extensive testing that the higher the device is located from the ground plane, the less effective is its ability to transmit the generated sound over a satisfactory distance so as to warn of the approach of the vehicle. Heretofore vehicle warning systems were not designed to be mounted in a location which is suitable for increasing the sound level ahead of the vehicle while at the same time decreasing the level within the vehicle. Some prior art systems utilized a large megaphone type horn to direct the sound signal. This type device permits the signal to be expanded and directed as it passes through the lengthy horn portion of the magaphone. The present invention provides the necessary direction and expansion of a noise signal over the appropriate distance by use of a system only a fraction of the length of a typical megaphone type system. Thus by virtue of the present system's unique design, the length of travel of the sound signals within the device is sufficient to allow complete expansion and direction of the signal and yet provide a system which is compact enough to be mounted in the grill or lower forward portion of an emergency vehicle. Further, existing devices do not contemplate the dual function of a sound and lighting system which may be mounted in the grill or lower forward portion of an emergency vehicle and which does not inhibit vital vehicle functions such as its cooling. The deficiencies in existing systems are pointed out by the fact that recent government specifications have been published to define a satisfactory warning system. These specifications require a high level sound carrying capability on the outside of the vehicle and at the same time require a decrease in the noise level within the vehicle.
Therefore it is an object of this invention to provide an emergency vehicle warning system which overcomes the shortcomings of existing warning systems.
It is a further object of this invention to provide a vehicle warning system which, while being very compact, permits the appropriate travel of sound signals over the required distance and direction so as to achieve maximum signal output.
Another object of this invention is to provide a warning system which may be quickly and easily mounted in the grill or bumper area of modern vehicles without affecting vital operations of the vehicle.
Yet another object of this invention is to provide a warning system which includes both sound and visual warning means in a compact device.
Still another object of this invention is to provide a compact audio visual warning system which may be mounted in the front of a vehicle by conventional means and which requires no extensive modifications for its mounting.
It is another object of this invention to provide a system which is attractive and which includes a trim ring which totally conceals all mounting portions of the system and is easily and quickly mountable and removeable.
A further object of this invention is to provide a system which is suitable for mounting on the lower forward portion of an emergency vehicle whereby it may direct sound signals in close proximity to ground level at a very high level and which produces a minimum of noise within the vehicle itself.
It is another object of this invention to provide a device which, while compact, is designed to cause the generated sound signals to move within the system a sufficient and calculated distance whereby the expansion and direction of the signals are carefully controlled to achieve maximum efficiency and the highest possible audio levels.